Spinning of highly viscous masses



L n A. SQHADE mm.

SPINNING 0F HIGHLY VISCOUS MASSES Filed Aug. 26; 1939 wm m w m n uwm A A M T.

Patented Jan. 21, 1941 UNITED STATES SPINNING F HIGHLY VISCOUS MASSES Arthur Schade and Paul Weber, Wiesbaden- Biebrich, Germany, assignors to Kalle & Co. Aktiengesellschaft,- Wiesbaden-Biebrich, Germany Application August 26, 1939, Serial No. 292,078 In Germany August 30, 1938 4 Claims.

The present invention relates to a spinning device for the production of broad bands or foils from highly viscous pasty sp masses- In making broad bands, especially sheets, from solutions of various materials, especially cellulose solutions, for instance viscose, spinning devices are used in which the solution is extruded from a long spinning slot into a precipitating bath or upon a support. Hithereto there has been re quired of solutions to be spun in this manner a fluidity such that there is no difficulty in expressing the mass through the spinning slot in such a manner that the same quantity of the mass is extruded per unit time throughout the m it is frequently an advantage in making sheets or other broad bands to start from very highly viscous spinningsolutions which behave essentially difierently from normal liquids and have scarcely any or indeed no tendency to flow. Thus for example very highly viscous solutions of cellulose in sulphuric acid or phosphoric acid are suitable for making sheets. If it is sought however to spin such highly viscous masses by means of the known devices to produce broad bands, diflicul-ties are encountered. For instance it is not possible with the usual spinning devices to extrude the highly viscous mass uniformly throughout the whole length of the spinning slot. Ihis is because the effect of an external pressure on such highly viscous masses is not auniform transmission of the pressure in all directions as is the case in normal liquids. If therefore into a chamber of a spinning device having a long spinning slot there is forced in usual manner a highly viscous mass the quantity which issues through the part of the slot lying near the entrance to the chamber is essentially greater than that which issues from the other parts of the slot. Thus, for example, if the point at which the viscous mass is introduced into the spinning device is located centrally with respect to the slot through which the material is extruded, the rate of extrusion through the middle portions of the slot will great- 5 ly exceed the rate at and'near its two ends. On

the other hand, introduction of the highly viscous mass at one end of the spinning device will result in comparatively rapid extrusion through the portions of the slot near the place of introduction and a gradual decrease of this rate as the other extremity of the slot is approached. Consequently, it is self-evident that extrusion of a highly viscous mass by means of such devices will not result in the formation-of sheets or bands of uniform thickness.

whole length of the spinning slot. Now however The present invention consists in a spinning device for spinning highly viscous masses, especially solutions of cellulose in sulphuric acid which is free from the said drawbacks of the known spinning devices. A constructional form of the new spinning device is shown in the drawing. Fig. 1 shows a longitudinal section of the device and Fig. 2' a cross section along line 1-1 of Fig. 1.

The new spinning device contains a feed worm 1 in the spinning chamber for supplying the spinning mass to the spinning slot. The axis of this worm should be parallel or substantially parallel to the length of the slot. The mass being spun issues therefore at right angles to the axisof the 15 worm. The worm should extend over the whole length of the slot and should be of such construction that at all parts of the slot the same mass of highly viscous spinning material is supplied per unit time and thus extruded uniformlyzo from the spinning slot. j

Suitable for the purpose of the invention is a worm having in the axial direction a; continuously altering i.- e. decreasing or increasing feeding capacity. Such a worm may be of conical shape or of decreasing pitch or may have a thread of decreasing cross section. The drawing shows how such a -worm has to be arranged in the spinning chamber.

l is the spinning chamber of the spinning device which isoi conical shape, 2- are the sides of the spinning slot, which sides may be adjustable to vary the width of theslot, 4 is an inlet for charging the highly viscous spinning mass. 3 is a conical feed worm the circumference of which touches the walls of the spinning chamber. The worm 3 is arranged in the spinning chamber in such manner that the feeding capacity constantly decreases from the end of the spinning chamber where the spinning mass is fed to the spinning chamber. 5 is an opening by means of which it is possible if necessary to circulate by pumping the highly viscous mass during the spinning operation so as to obtain a constant mixing of the mass.

With the device constructed according to this invention it is possible to make sheets or bands of uniform thickness from very highly viscous masses which are no longer fluid, but maybe cut by means of a knife.

We claim:

1. A spinning device for the production of foils, comprising a spinning chamber provided with a spinning slot, means for feeding a spinning mass to the said spinning chamber and a 55 feed worm in the said spinning chamber having its axis substantially parallel to the longitudinal direction of the said spinning slot and extending over the whole length of the slot. said worm being constructed to supply the same quantity of a pasty spinning mass per unit time'to all parts of the said spinning slot.

2. A spinning device comprising a spinningchamber of circular cross section which is provided with a straight spinning slot extending over the length of the chamber, means for feeding a spinning mass to the one end of the said spinning chamber and a feed worm coaxial with and,

extending over the whole length of the spinning chamber and touching on its circumference the wall of the chamber. said feed worm having a feeding capacity continuously decreasing from the point where the spinning mass is fed to the spinning chamber.

nearestlosaid larger end of the chamber termi-- nating short of said inlet opening, and -a rotatable, conical feed worm coaxial with and extending the entire length of said chamber, the

' periphery of said feed worm being in sliding contact with the walls of said chamber.

'SCHADE. PAUL WEBER. 

